The dynamic range of an imaging system can be defined by the range of light intensity levels that can be effectively captured by that system. In standard imaging systems (e.g., single-exposure systems), the system may be able to effectively capture only a small range of light intensity levels. For example, when an imaging system utilizes a short exposure time to produce an image, low-light intensity levels may be ineffectively captured. This may, for example, produce an image in which low-light intensity features (e.g., shadows or night scenery) are underexposed and lose detail. As another example, when an imaging system utilizes a long exposure time to produce an image, high-light intensity levels may be ineffectively captured. In this case, an image may be produced in which high-light intensity features (e.g., bright lights or light reflections) are overexposed and thus ineffectively captured.
Accordingly, in order to expand the dynamic range of a system, several techniques have been developed for producing high dynamic range (“HDR”) images in which a wider range of light intensity levels can be effectively captured. One of these techniques is the multiple-exposure method. In the multiple-exposure method, two or more images of the same scene can be captured, where the images are each exposed for a different amount of time. A final image may then be created by combining these multiple exposures. For example, in some multiple-exposure methods, a final image can be created by summing weighted pixel values from each of the exposures. Such an HDR system may, for example, clearly capture image features that range from dark shadows to bright lights.